Peer-reviewed articles have been evaluated by several researchers or subject specialist in the academic community prior to accepting it for publication. Also known as scholarly or refereed.
In most databases you may limit your search to peer-reviewed, scholarly, or refereed publications by selecting this filter.
There may be content in peer reviewed journals which is not peer reviewed. These may be book reviews, letters, or front and back matter. In most cases, though, the research articles within will be peer reviewed. Consult a librarian if you're not sure.
What is a peer reviewed article?